黄河上游沙漠宽谷段泥沙淤积以沙漠粗沙为主。粗沙推移质较之砾质推移质而言，其运动表现出显著的湍流扩散特性。粗沙颗粒与湍流涡团相互作用，运动过程极其复杂，进而加速形成黄河上游"新悬河"并导致严重的洪凌灾害。因此，开展粗沙推移质湍流扩散机理研究尤为必要。本项目基于沙漠粗沙颗粒的离散性特点，在开展野外风沙水沙过程观测之基础上，建立粗沙水流运动概化模型试验台；设计基于Matlab图像处理技术的颗粒运动状态可视化自动量测系统，测量试槽垂向水流速度场并统计不同水力因子驱动下的粗沙颗粒起动概率、时空位置及浓度等，采用互相关算法估算颗粒起动速度、瞬时运动速度；辅以建立并优化基于颗粒随机轨道方法的欧拉-拉格朗日固液两相流湍流数学模型，模拟颗粒起动后的湍流扩散过程；探索这种工业界工程热物理中常见的基于CFD的两相流分析方法在河流粗沙推移质湍流扩散机理研究中的应用前景，进而丰富沙漠河流泥沙动力学理论体系及其内容。

The components of sediment deposit in the upper reach of the Yellow river are mainly composed of desert coarse sediment.Compared with the moving characteristics of the gravel bedload，that of the sandy bedload shows significant characteristics of turbulent dispersion.The interaction between coarse sediment and turbulent as well as the whole moving process are both complicated which consequently accelerates the forming process of the new shape in the upper reach of the Yellow River and even causes serious water flood and ice disasters.Therefore，research on the turbulent dispersion mechanism of coarse sediment when necessary is of great importance.Taking into account of the discrete characteristics of desert coarse grains，one generalized model experimental instrument used for coarse sediment motion experiments is to be designed and constructed on the basis of the field observation and measurement on the aeolian-fluvial interaction process，configured with the Matlab image processing-based and visualized and automated measurement of moving coarse grains system for measuring the vertical flow field of the flume as well as collating statistics of the entrainment rate and spatial distributing position and concentration etc.On the basis of which，the cross-correlation algorithm would be used to estimate starting and instantaneous velocities of various coarse grains，thus the Eulerian-Lagrangian two-phase turbulent numerical model based on the stochastic trajectory method would be established and ultimately be verified and optimized to describe the turbulent dispersion process of grains after its starting moving，and by means of which，the CFD-based method of two-phase flow analysis commonly used in Engineering Thermal Physics field in industrial circle would be applied for researching on the turbulent dispersion mechanism of coarse sediment bedload for the prospect of application in river dynamics，which would enrich the theoretical system and the contents of the sediment dynamics of desert and river.